In passenger cars, as well as tractors, it is known to provide a rollover protection system to create a survival space for occupants in the event of vehicle rollover, having a rollover bar, for example, which is allocated to an individual vehicle seat or several vehicle seats and is concealed in its rest position in a cassette attached to the vehicle, from which it can be abruptly moved into an upper support position and locked in this support position on recognition of a vehicle accident.
Rollover bars generally used in practice typically consist of a U-shaped bar, whose tubular arms are guided vertically in vertical tubes of a module attached to the vehicle. A coil spring is arranged in the interior of each arm, which is biased by a holding device that can be released as a function of a crash signal of the vehicle sensor mechanism, so that the rollover arm, under the influence of the spring, is deployed in tenths of a second and locked in its support position by an appropriate locking device. The two tubular arms are then connected to each other by a cross-yoke, over which a cushioned impact element is generally mounted.
Examples of rollover bars, deployable or pivotable outward in the event of a crash and extending over the entire width of the vehicle, are described in DE 195 40 819 C2 and DE 197 12 955 A1.
A problem with such rollover bars that span the entire width of the vehicle is that often a so-called drawer effect is observed, which is understood to mean a tilting or jamming of the rollover bar during its activation, because of manufacturing tolerances or a lack of synchronization of the drives acting on the arms of the bar.
DE 198 38 989 C1 is referred to as an example of a rollover protection device allocated to only one vehicle seat, with a rollover element that can be deployed independently of a rollover element that is allocated to another vehicle seat. In it, a rollover device is disclosed, consisting of a cassette that is fastened to the vehicle, a rollover element in the form of a profile bar element extending over the entire width of the cassette, secured and guided in guides and deployable in the cassette, a locking device for self-locking of the deployment movement and a spring drive system for deploying the profile bar element and with a mechanical holding device for holding the rollover element in a rest state against the bias force of the compression spring of the spring drive system.
The furnishing of such a rollover protection device for each vehicle seat disadvantageously causes a large number of components and overall high weight for the entire rollover protection system.
The rollover protection systems just described, like the rollover protection devices known from practice, also have the drawback that a pass-through capability between the vehicle spaces bordering the rollover protection device and its guide devices is often limited, owing to the drive of the rollover bar on both sides. The rollover protection devices, generally arranged in the center in a vehicle seat, therefore do not permit any pass-through or permit only a small-dimensioned pass-through between an occupant space and a stowage space on the rear of the vehicle, since only limited spacing is available between the rollover protection devices of the corresponding seats.
Even more limited are the capabilities for achieving a pass-through with rollover protection devices that are fastened as a standing unit on a mount attached to the body, for example, a vehicle transverse wall adjacent the rear of a vehicle seat.
This type of advantageous embodiment of a rollover protection device, from the standpoint of manufacture, is described, for example, in DE 195 01 584 C2, DE 43 14 538 C3 and EP 1 084 914 A2.
In addition, it is known from DE 195 01 522 A1 to arrange a support element in the two rear side wall areas of the vehicle body, when lowered in its rest position in the vehicle side wall area, and can automatically be moved into an active position in the event of an accident.
It is also known from DE 103 57 053 A1 to arrange deployable rollover bars in a driver's side or passenger's side door.